1. Field of Invention
The present invention relates to bottom wall structure, and more particularly to a lightweight bottom wall structure for a play yard, pen, and cot, which has a rigid, simple, and strong structure in lower manufacturing cost to evenly distribute and support a downward force of a user""s weight.
2. Description of Related Arts
Play yard, pen, and cot are used to restrict the movement of a baby who is able to trail or walk when the parents cannot keep their eyes on their babies. A conventional play yard, pen, or cot comprises a boundary frame having a receiving cavity and a supporting board disposed in a bottom of the receiving cavity for supporting the user""s weight. However, the conventional play yard, pen and cot have several drawbacks.
In order to provide a rigid structure to support the user""s weight, the supporting board must be constructed to have a tension-supporting surface. It is worth to mention that tension-supporting surface provides a predetermined tension force evenly distributed on the supporting board, wherein when the downward force of the user""s weight is greater than the tension force, the supporting board will be cracked or even broken. However, the supporting board is a rigid wooden board or cardboard that the concentrated downward force may crack the supporting board easily, especially when the user, such as a young child, jumps on the supporting board. Therefore, the rigid supporting board may not be the best solution for the play yard, pen, and cot.
Moreover, the supporting board is bulky and heavy for storage and transportation. For saving space for travel and storage, most of the play yards, pens and cots are made foldable to reduce their storage and packing sizes. However, the supporting board must be taken out from the boundary frame in order to fold up the play yard, pen, or cot, that may loss the ordinary features such as portable and compact size of the play yard, pen, and cot. Even though the supporting board is constructed of a plurality of sections that allows the supporting board to be folded into a compact size and unfolded for use, the fold-up structure of the supporting board cannot provide the high tension-supporting surface. In other words, the foldable supporting board cannot rigidly support the user thereon.
A main object of the present invention is to provide a lightweight bottom wall structure for play yard, pen, and cot, which has a rigid, simple, and strong structure to evenly distribute and support a downward force of a user""s weight.
Another object of the present invention is to provide a lightweight bottom wall structure for play yard, pen, and cot, wherein the bottom wall is a durable and flexibility for providing a high tension-supporting surface to enhance the life span of the bottom wall.
Another object of the present invention is to provide a lightweight bottom wall structure for play yard, pen, and cot, which provides a substantial support without altering or complicating the original structure of the play yard, pen, and cot.
Another object of the present invention is to provide a lightweight bottom wall structure for play yard, pen, and cot, which can incorporate with any play yard, pen, and cot having a foldable structure. In other words, the play yard, pen, and cot can be folded with the bottom wall into a compact unit without altering both the bottom wall and the original structure of the play yard, pen, and cot.
Another object of the present invention is to provide a lightweight bottom wall structure for playyard, pen, and cot, wherein no expensive or mechanical structure is required to employ in the present invention in order to achieve the above mentioned objects. Therefore, the present invention successfully provides an economic and efficient solution for providing reinforced supporting configuration to the user.
Accordingly, in order to accomplish the above objects, the present invention provides a play yard, pen, and cot, comprising:
a boundary frame constructed to support a fabric made boundary shelter and comprising a bottom frame defining a central window; and
a bottom wall comprising a first layer having a tension surface and a second layer overlapped with the first layer to define a receiving groove between the first and second layers, wherein the bottom frame has a size and shape adapted to be fittedly received in the receiving groove so as to mount the first layer covering the central window to form the tension surface.